Process of manufacturing artificial cork



Patented Aug. 25, 1931 i,sz0,411

UNITED STATES PATENT OFFICE- ENRIQUE VINCKE, OF BARCELONA, SPAIN, ASSIGNOR, BY MESNE ASSIGNMENTS TO ARMSTRONG CORK. COMPANY, OF LANCASTER, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA PROCESS OF MANUFACTURING ARTIFICIAL CORK No Drawing. Substitute for applications Serial No. 659,417, filed August 25, 1923, and Serial No. 663,932, filed September 20, 1923. This application filed January 4, 1927. vSerial No. 159,017.

It is well known, for the purpose of economically using cork waste of cork industries, that a number of industries have developed for the purpose of utilizing such cork waste. By reason of the large quantities of cork waste thus now required, it has become necessary to employ virgin cork bark and the low grades 'of cork bark in addition to cork waste. I I

In the utilization of cork waste, with or without virgin cork bark or low grades of cork bark, the cork material is divided up into smaller portions by sawing, cutting, grinding or chipping, resulting into the so-calledgranulated or ground or chipped cork. In such processes of reduction in dimension of the-cork material, it is necessary to separate the cork particles by graduated sieves.

Such processes are objectionable for the reason that the manufacturer rarely has use resulting from the'aforesaid process of reduction, inasmuch as the particular industries are limited to special sizes, and the disposal of the undesired sizes of cork particles results in at least a partial loss.

The aforesaid processes also introduce the further objection that, unless the outer hard and crusty bark, i. e., the so-called hard back has been removed in advance, which is in most cases impracticable, the aforesaid procedure of reduction gives rise to the presence of particles of the outer bark, andadditional processes are necessary for the purpose of eliminating this objectionable ingredient.

In the use of granulated cork, formed as above described, the same is introduced into suitablemolds, either admixed with or without a binder, compressed and baked together, the'cork particles are bound to one another in haphazard relation of the cellular structure of the cork particles. Pursuant to the present invention the step of granulation is omitted, and I proceed in the following manner. After the outer hard back of the cork has been removed,

ness of paper. are then reduced to flakes or scales by 'cutting, grinding, chipping or other suitable' for all the various sizes of granulated cork the cork is cut into sheets or films of the thick- The resulting sheets or films procedure for the reduction of size, but prserving the flake or scale form wherebythe dimensions of the surface of each flake or scale are greater than its thickness.

be selected to be wholly or largely volatile during or subsequent to the molding operation. o

' An improved method of manufacturing the composition cork from cork flakes or scales consists in cutting sheets of films of a thickness comparable to that of paper by severing on planes substantially parallel to the yearly layers of the cork bark and reducing the sheets or' films to'fiakes or scales as above described. The resulting cork flakes or scales are charged into a mold of standard construction and having a fiat bottom face or upon a moving platform as above described, and are subjected to vibration, whereby the flakes or scales are located in substantially face to face contact, and intertwined with respect to one another, while being maintained in substantially parallel planes to one another and with the flat faces of the flakes or scales disposed substantially parallel to the flat bOltOIIl face of the mold or moving platform.

As set forth 'hereinabove, the original structure of the cork is entirely lost in the manufacture of artificial or composition cork by using granulated cork as heretofore made, by reason of the individual granules being assembled in haphazard relation of the cel- In my* yearly layers and yielding a cork product, the structure of which is comparable to that of natural cork of the higher qualities and in addition yielding amuch more flexible and 5 elastic product.

My invention possesses the distinct advantage as compared with granulated cork in that the product may be of continuous web form, of any desired thickness or width or length. A further advantage of my invention resides 'in that the procedure does not give rise to any loss in cork flour, as in the case of granulated cork. The flakes or scales formed in the procedure of my invention by reason of their thinness are readily cleansed or dyed as desired.

For the purpose of severing the cork bark on planes substantially parallel. to the yearly layers, it is advantageous to flatten out the harvested bark and to employ rectilinear severing devices such as rotating knives. Such severing is substantially perpendicular to the radial walls of the cellular structure of the cork, thereby providing a coeflicient of flexibility greater-than that when the flakes or scales are severed in other relation to the cellular structure of the cork.

This application is a substitute for my application Serial No. 659,417, filed August 25th, 1923, and for my application, Serial- No. 663,932, filed September 20th, 1923, both entitled Process of manufacturing artificial and composition cork and the product of the same, wherein said co-pending applications I claim cork products formed from flakes or scales which are bonded to one another by means of heat and pressure only and without the use of an adhesive.

In this application, the subject matter is directed to the formation of molded'products formed of cork flakes or scales and bonded to one another by the use of an adhesive under heat and pressure.

The specific final forms of cork products are derived from my molded cork product pursuant to the usual procedure. Thus, sheets for gasket uses are formed by severing my molded product corresponding to the desired thickness or thicknesses. The resulting sheets of reduced thickness are then punched to obtain the desired contour and perforations required by the particular types of gaskets, as for automotive engines and gasket uses generally. By severing my molded cork product to obtain very thin sheets, and cutting such thin sheets for appropriate widths, material such as tipping material and the like are derived. Such re sulting cut lengths or ribbons may be attached to one another by. adhesive or the like and wound as rolls, if desired.

In the production of cork products of the various forms embodying my present invention, the bonding between the mutually engaging flat particles is partially e'fiected by other and therewith of the whole, I have discovered that a greatly reduced quantity of adhesive is required to complete the bonding of the respective particles to form the mass of any particular product, and in many instances, the amount of adhesive may be re duced in amount to a quantity less than onetenth of the adhesive required pursuant to prior practices.

Whereas, I have described my invention by reference to specific forms thereof, it will be understood that many changes and modifications may be made without departing from the spirit of the invention.

I claim:

1. The process of producing cork products of superior flexibility which comprises subjecting cork to a severing operation along lines substantially perpendicular to the radial walls of the cells of the cork, subjecting the resulting severed sheets or films to a reaking-up action to derive cork scales, applying adhesive to the same, assembling the adhesive-applied scales while subjecting the same to relative movement to effect substantially face to face contact of the scales with one another and molding the same.

2. The process of producing cord products of superior flexibility which comprises subjecting cork to a severing peration along lines substantially perpendicular to the ra dial walls of the cells of the cork, subjecting the resulting severed sheets or films to a breaking-up action to derive cork flakes, applying adhesive to the same, assembling the adhesive-applied flakes while subjecting the same to relative movement to effect substantially face to face contact of the flakes with one another and molding the same, to form a web-like product.

3. The method of forming cork products which comprises charging into a mold hav ing a flat bottom face cork particles having substantially parallel opposite flat faces the dimensions of which are considerably greater than the thickness of each particle, said particles being cut on planes substantially parallel to the yearly layers of growth of the natural cork, whereby said flat particles are disposed within the mold to have their flat faces substantially parallel to the flat bottom face of the mold, the flat faces of the particles being substantially parallel to one another and overlapping one another, applying pressure to the charged particles to effect interfelting between the mutually engaging flat surfaces, and subjecting the compressed charge to an elevated temperature to bond the particles to one another.

4. The method of forming cork products which comprises charging into a mold having a flat bottom face cork particles having substantiall parallel opposite flat faces the thickness 0 each particle being substantially that of paper confetti, said particles being cut on planes substantially parallel to the yearly layers of growth of the natural cork, whereby said flat particles are disposed Within the mold to have their flat faces substantially parallel to the flat bottom face of the mold, the flat faces of the particles being substantially parallel to one another and overlapping one another, applying pressure to the charged particles to effect interfelting between the mutually engaging flatsurfaces, and subjecting the compressed charge to an elevated temperature to bond the particles to one another.

In testimony whereof I have signed this specification this 29th day of November, 1926.

ENRIQUE VINCKE. 

